In an air seeder, agricultural materials such as seed, fertilizer, and chemicals are dispensed from respective holding tanks into an air stream that carries the materials through a distribution network to an array of furrow openers mounted along the width of the implement frame which create furrows in the soil surface. In some types of air seeders, the distribution network includes larger tubes carrying product from the holding tanks to manifolds where the air stream and entrained agricultural products are divided and directed into smaller delivery tubes, and the output of the final delivery tube in the network dispenses the agricultural products into the furrows. In other types of air seeders, a single delivery tube may carry products directly from the product tanks to each furrow.
In large modern air seeders, there may be 100 or more furrow openers spread across the width of the implement and it is desirable to monitor the flow of agricultural products to the furrow openers to ensure that the system is working properly. Blockages due to low air flow, plugged furrow openers, empty product tanks, meter failure, or the like can result in stoppages in product flow. Also the rate of product flow may be less than desired for various reasons. To address this problem, monitors and sensors have been developed to monitor product flow in these distribution networks.
U.S. Pat. No. 5,831,542 to Thomas discloses an air seeder blockage monitoring system operative to detect seeds and like agricultural products flowing in a conduit and indicate to the operator that products are flowing, and also the rate of product flow.
Such monitors are commercially available from various sources. Intelligent Agricultural Solutions of Fargo, N. Dak. manufactures a wireless blockage monitor where sounds from a diaphragm in a bend of a seed tube are carried through a tube to a control unit on the air seeder which essentially “hears” the sounds in each tube, and then sends an indication of product flow in each tube through a wireless connection to a display on the tractor. Thus there are no electric wires to each sensor, but a hollow tube must be installed from each sensor to the control unit.
Agtron Enterprises of Saskatoon, Canada manufactures a blockage and flow monitor with a sensor that uses infra-red light to detect flow. The sensors are connected to each other by wires in a daisy chain arrangement, and to a receiver which then sends readings from each sensor through a wireless connection to a display on the tractor. Wires carry power to each sensor, and also carry the sensed information from one sensor to the next.
Agri Motive Products of Warren, Ind. and Micro-Trak Systems, Inc. of Eagle Lake Minn. also manufacture such blockage monitors for air seeders.
While it is known to monitor product flow in only some delivery tubes, it is commonly desired to monitor product flow to each furrow to avoid areas of unseeded ground. With the very large number of furrow openers on current air seeder implement, and given that often each furrow opener will create furrows for two separate products with two separate product delivery tubes thus going to each furrow opener, hard connections of tubes and/or wires to each sensor on each delivery tube can become complicated and cluttered.
Additionally, these sensors are usually installed near a manifold where each delivery tube starts rather than being installed near where the furrow opener ends to simply wiring. To install one or two sensors near each furrow would require a large amount of wire and make the wiring of the system very complicated. The major problem of having a wired sensor by the opener is that trash and rocks distributed by the operation can rip off any wires. Also shank trips over rocks can cause a lot of stress on any wires. However by installing the sensors on the delivery tubes near the manifold, if a blockage should occur near the end of the delivery tube, it will take some time for the blocked delivery tube to fill up with agricultural product back to the sensor so that the sensor senses the “blockage”.